eGen COBOL Code Generator Reference

 

This section contains reference pages for the BEA WebLogic Java Adapter for Mainframe eGen COBOL Code Generator (eGen utility). This information includes the rules for writing the script file that controls the code generator.

 

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eGen COBOL

The eGen utility maps a COBOL copybook into a Java class.

Synopsis

Invoke the utility with the following command:

java com.bea.jam.egen.EgenCobol scriptfile

where:

java

is the name of the Java virtual machine executable in the Java Development Kit (JDK).

com.bea.jam.egen.EgenCobol

is the full class name of the eGen utility.

scriptfile

is the script file that controls the eGen utility. You must write this script file on an application-by-application basis. (See Listing 2-1 for an example).

If the JAM installation bin directory has been added to your path, then the eGen utility may also be invoked with the command:

egencobol scriptfile

Listing 2-1 Example of scriptfile.egen

### example script
#

view demo.CustomDataView from emprec.cpy

service demoService accepts CustomDataView returns CustomDataView

page demoPage "Demo Page"
{
    view demo.CustomDataView

    buttons
    {
              "Try It" service(demoService) shows demoPage
    }
}

servlet demo.DemoServlet shows demoPage

Script Syntax Reserved Words

The reserved words shown in Table 2-1 must be used as specified in the Grammar section.

Note: A reserved word can be used as an identifier if it is enclosed in either single or double quotation marks (refer to General Rules).

Table 2-1 Reserved Words

accepts	buttons	class	client	codepage	ejb
from	generate	group	is	method	page
reset	returns	server	service	servlet	shows
support	view	xml

 

General Rules

• The `#' character and all following characters on the same line are a comment. Use the `#' character to specify commented text.

• The character sequence "//" and all following characters on the same line are a comment. Use the "//" characters to specify commented text.

• The character sequence "/*" and all following characters until the occurrence of the sequence "*/" are a comment. Use the "/*" characters to specify commented text that extends beyond one line.

• White space (including newlines) is not significant, except when it is used to seperate tokens. White space includes newlines, carriage returns, tabs, spaces, etc.

• Any sequence of letters, digits, underscores, or periods is a word.

• Any word that does not match a reserved word is an identifier.

• Any sequence of characters is treated as an identifier if it is enclosed in either single or double quotes. This allows the use of reserved words and sequences that contain spaces.

Grammar

The eGen COBOL script grammar uses a modified Backus-Naur Form (BNF) syntax, which is used in many industry-standard software reference guides. BNF syntax specifies a context-free grammar. Reserved words are shown in bold. Comments are in italics preceded by a dash (. ).

script:

definition | script definition

fulldefinition:

generate definition | definition

definition:

viewdef | servicedef | servletdef | ejbdef | classdef | pagedef

viewdef:

view viewname from copybook | viewdf viewmodifier

viewmodifier:

codepage codepagename | support xml

servicedef:

service servicename accepts fullViewname returns fullViewname

servletdef:

servlet classname shows pagename

ejbdef:

clientejb | serverejb

clientejb:

client ejb classname ejbregistration { clientmethods }

serverejb:

server ejb classname ejbregistration { servermethods }

classdef:

client class classname { clientmethods }

pagedef:

page pagename title { view viewname buttons { buttonlist } }

buttonlist:

buttondef | buttonlist buttondef

buttondef:

servicebutton | ejbbutton

clientmethods:

clientmethoddef | clientmethods clientmethoddef

clientmethoddef:

method methodname is servicename

servermethods:
servermehtoddef | servermethods servermethodddef

servermethoddef:
method methodname (fullviewname) returns fullviewname

servicebutton:

buttonname service ( servicename ) shows pagename

ejbbutton:

buttonname ejbmethod ( fullViewname ) returns fullViewname

viewname:

classname

fullViewname:

viewname | viewname [ codepagename ]

copybook:

identifier

. An identifier that names a file containing a COBOL data definition.

servicename:

identifier

. An identifier that matches a resource definition in your jcrmgw.cfg file

pagename:

identifier

. An identifier that names a page definition.

codepagename:

identifier

. The name of a codepage to be used for character translation to/from mainframe data formats. This must be a codepage supported by the JDK being used.

methodname:

identifier

. The name to be given to a generated Java method.

classname:

identifier

. An identifier that names a Java class, including any package name.

ejbregistration:

identifier

. The name that will be used to register the home interface for an EJB.

title:

identifier

. The title to be placed into the HTML generated for a page.

buttonname:

identifier

. A button name that will be used in the HTML generated for a page.

ejbmethod:

identifier

. An EJB classname and method specification that should look like this:

package.ejbclass.method

or

ejbclass.method

Results of Running the eGen COBOL Code Generator

The specified COBOL copybook is parsed for each DataView definition (described in the JAM Programming Reference section of this guide) and a Java source file for the specified DataView class is generated in the current directory.

If XML support was requested, then the following files are also produced:

viewname.dtd - DTD file

viewname.xsd - XML Schema file

For each client class definition, a Java source file is generated in the current directory for the specified class.

For each EJB definition, three Java source files and a deployment descriptor text file are generated in the current directory. The names of the generated files are listed in Table 2-2. 
  
 

Table 2-2 Generated Files for EJB Definitions

Name of File	Purpose
classnameHome.java	EJB Home Interface
classnameBean.java	EJB Implementation class
classname.java	EJB Remote Interface
classname-jar.xml	EJB Deployment descriptor
wl-classname-jar.xml	WebLogic Deployment Info